Contrasting colors for type matrices



Jan. 12, 1954 w HEINECKE 2,666,002

CONTRASTING COLORS FOR TYPE MATRICES Filed Sept. 29, 1951 IN V EN TOR.

W/LL/AM HE/A/ECKE BY A TTORNE Y Patented Jan. 12, 1954 OGNTBASTINGCOLORS FOR TYPE MATRICES 9 Claims.

LThisJappIication is a continuation-in-part of my co-pendingapplication, Serial No. 83,325,

filed March 25, '19i9now abandoned.

The invention relates to the provision of contrasting colors on matricesfor integral line'type so that .an identifying character thereon mayhave a background which will renderthe character easily visible.

In the casting of integral-line type fromconventional type metal theusual procedure comprises the selection of brass matrices for each typefrom their respective magazines or chutes by .a manually operated keyboard. The se lected matrices are automatically placed in aclampingdevice to form a line and then-molten metal is forced into thedies of the matrices to cast a slug of the type.

During the above mentionedoperation the operator is never able tosee thedie portion of the matrix and the only way by which he may determinewhether he has selected the proper matrix is from a small identifyingcharacter corresponding to the type character of the die and which isstamped on the opposite edge of the matrix. These identifying charactersare customarily considerably smaller than the corresponding die so thattheirvisibility is not great.

Furthermore, in course of use, the matrix becomes covered with a darkgrime of lead sulfide from the type metal as Well as of graphite whichis employed as a lubricant for proper sliding of the matrix in themagazine chute and the automatic sorting means for returning thepreviously used matrix. This grime is'periodically removed by variousagents such as described in my copending application, Serial Number705,481, filed October 24, 1946, which issued October 28, 1952 as Patent2,615,825.

Whether the matrix is clean or dark there is usually insufficientcontrast in color of the identifying character to enable the operator toread the "line being formed by the matrices. Vari ous means and methodshave been proposed to provide sufficient contrast such as the employmentof dark backgrounds and whitened characters such as described in UnitedStates Patents Nos. 1,466,437 and 1,796,023. In these patents nosuggestion is given as to how the back ground may be obtained except bysome chemical action such as oxidation. So faras I am aware, the onlychemicals that have been em--- ployed commercially for this purpose havebeen copper nitrate or copper carbonate, wet proo- 2 esses. These wetprocesses are carried out by boiling the solution in to produce a filmwhich will last only about six months in ordinary use. Furthermore, inpractice the solutions not only'attack or plate the desired edgeportions but the liquid creeps even into the die thus impairing itsaccuracy. These processes are necessarily delicate, and are not carriedout in the absence of special service shops. Consequently the process isof little use to the Linotype users except those comparatively few wheresuch shops exist.

An object of the invention is to provide a dry method for darkening thematrices which can be carried out by any Linotype operator withoutdanger to the dies and which will utilize only simple equipment salableas an article of commerce.

I have found that a highly satisfactory degree of color contrast betweenthe identifying charactor and its background may be obtained by merelyfilling the indentations of the stamped identifyingcharacter with aninert white chalky pigment and darkening the background or matrix edgeface by the formation of a sulfide coating thereon.

I have found that if the matrices to be treated after they are cleanedand dried are held in a clamp with their lateral faces together andtheir identifying characters more or less alined, the pigment may beapplied simply by rubbing the characters with chalk, and the characterfaces may be darkened by the application of a sulfur emitting compound.The nature of the sulfur compound to be used is of the utmost importanceas it must come in intimate contact with the surface to be darkened andyet must be such that no excess can be left on the matrix and must notemit any offensive odor. If the darkening compound is ap lied in liquidsolution there is great danger that the liquid be drawn in between thematrices by capillary attraction so as to darken other portions of thematrices, and attack the dies. In my invention, 2, dry organic sulfurcompound preferably on a carrier is heated to its melting and/ordecomposition temperature adjacent the surface'to be darkened. While theexact nature of the decomposition products vary, their odor is notnoticeable and their action can easily be localized to the surfacedesired. I

I have found that of a large number of sul fur compounds the moresatisfactory ones are contact with the matricesthose which also containamino or substituted amino groups, and of these, those which contain thegroup are especially desirable. other tautomeric compound which willform such a group will also be satisfactory.

I have found that the sulfur compound most satisfactory is thio-urea or,its equilibrium isomer, ammonium thiocyanate. Herein both of thesecompounds will be designated as thio-urea since the thiocyanate islargely converted to thio-urea at the temperature employed.

The compound such as thio-urea is preferably impregnated in a porousstrip of absorbent material, then dried, and the strip laid on thematrices at the area to be darkened. The thiourea is then heated aboveits melting point and the sulfur emitted during its, at least partial,decomposition forms a film of sulfide of copper on the matrix. While thefilm is of slight thickness and hardly susceptible of analysis, itappears to be cuprous sulfide owing to its almost black C010r and thefact that it is formed in a reducing atmosphere.

In the accompanying drawing showing, by way of example, two of manypossible embodiments of the invention,

Fig. l is a perspective showing a matrix,

Fig. 2 is a plan of a clamp holding the matrices therein, and

Figs. 3 and 4 are diagrammatic representations of means for heating theimpregnated strip.

lhe brass matrix it is shown in Fig. l is provided at its rear face itwith a die or mold (not visible in Fig. l) in which the types are cast.

The front or background face i2 is provided with an identifyingcharacter 13 corresponding to the die character. The character It isusually formed as an indentation merely stamped or punched in the brasswithout consideration as to the size except that it must be well withinthe margins of the face I2 and so it is much smaller than the type castfrom the matrix. These characters afiord the only means for the operatorto read what he is setting up. The matrix is provided with an car It anda toe [5 at opposite ends of the face l2.

In carrying out my invention a number of matrices are clamped in anysuitable means such as a clamp it having sides i? and end piece iswherein the matrices are held tightly between the end piece [8 andfollower iii, the pressure being supplied by a screw 20 received in asuitable mount 2|.

All the faces 12 are upwardly exposed and the characters it more or lessalined. A colored pigment or ceramic color is rubbed into indentationsof the characters and any excess is wiped off to leave the faces l2clean. The pigment should be substantially inert toward sulfur and ofcourse not greatly injure brass. Calcium sulfate, for instance, issatisfactory and may be used either in stick or powdered form. Of coursethe freer the indentations are from grime and dirt the better thepigment will be retained.

After the characters are whitened or colored,-

a strip, preferably dry, of fibrous or absorbent material 22 impregnatedwith an organic sulfur compound such as thio-urea, is laid over thefaces l2 between the ears l5 and toes 46. The strip is then heated todecompose at least a portion of the thio-urea, as evidenced by thedarkening of the faces, bymeans of an infra-red Obviously any '4 radiantheater 23 or other heating means such as a heated roll 24. The dark filmon the face thus formed is not substantially affected by sulfuric orchromic acid, amines or any of the agents used for cleaning thematrices. The contrast between the colored pigment e. g. calcium sulfateand the black background affords excellent visibility of the character.The film so produced is resistant to the action of air and heat and nomaterial change has taken place over a test period of several years onmatrices so treated and cleaned.

As previously pointed out above many other compounds may be used insteadof the thio-urea, such as rubeanic acid (dithiooxamide),diphenylthiocarbazone, thiosemicarbazide,thioglycolicbeta-aminonaphthalide, ditolylthiourea, and thiocarbanilide.

The strip or ribbon 22 is preferably flexible so as to afford closecontact with the faces, and may be of paper or cloth. However thesematerials frequently char at the desirable temperatures (C. and above)and present problems of cleanliness. Asbestos paper may be used althoughstiffness frequently prevents good contact with the faces. Spun-glassclothis the most desirable of all materials as it is stable to heat,inert to thio-urea, possesses great flexibility and presents no problemof cleanliness during operation.

The compound may be impregnated in the fibers of the ribbon 22 in anysuitable manner although it is preferable that a binder inert to thesulfur compound be employed to cause the latter to adhere to the ribbonwhen the latter is dry if glass is the material. Nitro-c'ellulose orcollodion is suitable. For example a mixture of thio-urea,intro-cellulose and ethyl lactate with a little oil of juniperempyreumatic and-ricinus oil as plasticizer is satisfactory. Thismixture may be thinned, if too viscous, with alcohol and/or nitrobenzenefor impregnation by immersion. The properties are not critical. Thematerial of the ribbon and/or the binder appear to absorb, temporarilyat least, a portion of the decomposition products.

If for any reason the dark film of sulfide of copper must be removed itmay be done by the use of nitric acid. Care must be exercised lest thenitric acid reach the die portion since this reagent readily attacks thebrass.

The sulfide film is not attacked by amines used for cleaning thematrices such as described in my above mentioned application Serial No.705,481. However film formed by the copper carbonate or copper nitrateprocess are quickly lost.

The thio-urea does not emit any appreciable odor as is true whensolutions of soluble sulfides or hydrogen sulfide are used. The brass isquickly darkened by the decomposition products of the thio-urea however.One reason for this may be due to a formation of small amounts ofammonia which are absorbed on the brass and so render the surfaceactive.

While I have described the darkening process part1cularly with respectto matrices the same general method may be employed for producingsulfide films on metals generally. The amino products are particularlyeffective for use on metals which form ammonia complexes, such ascopper, zinc, nickel, cobalt, silver and the like.

While the melting points of the sulfur compounds may vary widely Iprefer to employ those.

which are solid at room temperature andhave a melting point below 600 F.

As will be apparent to one skilled in the art, the ribbon 22 shouldpreferably be substantially free from materials which would fix sulfurat the melting point of the sulfur compound since their presence wouldcause sulfur or the sulfur-bearing products of decomposition to be fixedin the ribbon and therefore such products would not be available todarken the matrix. Otherwise additional amounts of the impregnant mustbe added to allow for the formation of fixed sulfur, with no additionaldarkening of the matrix.

The presence in the ribbon of metals, or their reactive compounds, whichoccur in the brass of the matrix, such as copper, would obviously causeto be fixed in the ribbon at least a part of the sulfur-bearing productsof decomposition and prevent efficient darkening of the matrices.

Likewise, when thio-urea, or similar compounds containing the H2NPJgroup mentioned above, are used as impregnants, the ribbon shouldpreferably be free from materials which form sulfur containing reactionproducts stable at temperatures above which the dzhio-urea or thesimilar compounds are decomposed. It is obvious that the formation ofsuch reaction products would require higher heating temperatures thanwould be necessary if there were no chance for the reaction products toform.

Whatever the nature of the ribbon fibers, it is of course preferablethat they be inert with respect to impregnated sulfur compound and itsdecomposition products. Likewise it is preferable that the ribbon fibersbe unafiected by, or inert to, heat at a temperature below the maximummelting and/or decomposition temperature for the sulfur compound setforth above, namely 600 F. Furthermore the ribbon is preferablysubstantially porous to permit diffusion of the fluid decompositionproducts so as to favor a uniform degree of coloration over the matrixface.

The invention claimed is:

1. A method for improving the visibility of characters punched in brasscomprising filling the indentations of the characters with asubstantially inert white pigment and melting thiourea adjacent thesurface in which the characters are punched.

2. In combination, a ribbon of Woven spun glass, thio-urea within theinterstices of the ribbon and a binder for anchoring the thio-urea tothe fibers of the ribbon.

3. A combination as in claim 2 said binder being nitro-cellulose.

4. A method for improving the contrast between a brass type matrixidentifying character and the surface of the matrix in which thecharacter is stamped comprising filling the indentations of thecharacter with a chemically and thermally inert light colored pigment;applying to the surface in which the character is stamped a stripimpregnated with thio-urea, and applying sufficient heat to the strip todecompose at least a part of the thio-urea.

5. A method for darkening the background surfaces of brass type matrixcharacters comprising arranging a plurality of matrices so that thebackground surfaces all lie in substantially a common plane, thenclamping the matrices tightly together, disposing a dry ribbonimpregnated with an organic compound containing the group on saidsurfaces, and then applying sufficient heat to the ribbon to decomposeat least a part of the compound, whereby a dark coloration is obtainedon said surfaces.

6. An article for use in darkening selected brass matrix surfacescomprising a ribbon of woven glass fibers impregnated with thio-urea,nitrocellulose as a binder to anchor the thio-urea to the fiber andricinus oil as plasticizer for the nitrocellulose.

'7. A method for darkening the surfaces of brass type matricescomprising arranging a plurality of matrices so that the surfaces alllie in a common plane, then clamping the matrices tightly together;disposing a dry ribbon of chemically and thermally inert materialimpregnated with a normally dry stable solid organic sulfur compoundhaving a melting point below 600 F. on said surfaces, and then applyingsufiicient heat to the ribbon to decompose at least a portion of thecompound.

8. A method as in claim 7 said compound also having an amino group.

9. A method as in claim 8 said amino group being a primary amino group.

WILLIAM HEINECKE.

References Cited in the file of this patent UNITED STATES PATENTS NumberName Date 1,844,199 Bicknell et al. Feb. 9, 1932 1,867,658 Dreyfus July17, 1932 2,297,909 Neely et al. Oct. 6, 1942 2,311,613 Slayter Feb. 16,1943

5. A METHOD FOR DARKENING THE BACKGROUND SURFACES OF BRASS TYPE MATRIXCHARACTERS COMPRISING ARRANGING A PLURALITY OF MATRICES SO THAT THEBACKGROUND SURFACES ALL LIE IN SUBSTANTIALLY A COMMON PLANE, THENCLAMPING THE MATRICES TIGHTLY TOGETHER, DISPOSING A DRY RIBBONIMPREGNATED WITH AN ORGANIC COMPOUND CONTAINING THE
 6. AN ARTICLE FORUSE IN DARKENING SELECTED BRASS MATRIX SURFACES COMPRISING A RIBBON OFWOVEN GLASS FIBERS IMPREGNATED WITH THIO-UREA, NITROCELLULOSE AS ABINDER TO ANCHOR THE THIO-UREA TO THE FIBER AND RICINUS OIL ASPLASTICIZER FOR THE NITROCELLULOSE.